EP0914195B1 - Method for separating a catalyst by membrane electrodialysis - Google Patents

Method for separating a catalyst by membrane electrodialysis Download PDF

Info

Publication number
EP0914195B1
EP0914195B1 EP97919434A EP97919434A EP0914195B1 EP 0914195 B1 EP0914195 B1 EP 0914195B1 EP 97919434 A EP97919434 A EP 97919434A EP 97919434 A EP97919434 A EP 97919434A EP 0914195 B1 EP0914195 B1 EP 0914195B1
Authority
EP
European Patent Office
Prior art keywords
solution
mol
catalyst
electrodialysis
process according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP97919434A
Other languages
German (de)
French (fr)
Other versions
EP0914195A1 (en
Inventor
Eric Fache
Dominique Horbez
Philippe Leconte
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rhodia Polyamide Intermediates SAS
Original Assignee
Rhodia Polyamide Intermediates SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rhodia Polyamide Intermediates SAS filed Critical Rhodia Polyamide Intermediates SAS
Publication of EP0914195A1 publication Critical patent/EP0914195A1/en
Application granted granted Critical
Publication of EP0914195B1 publication Critical patent/EP0914195B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42—Separation; Purification; Stabilisation; Use of additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
    • B01D61/44—Ion-selective electrodialysis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J38/00—Regeneration or reactivation of catalysts, in general
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J38/00—Regeneration or reactivation of catalysts, in general
    • B01J38/48—Liquid treating or treating in liquid phase, e.g. dissolved or suspended
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/584—Recycling of catalysts

Definitions

  • the present invention relates to a method of separation by electrodialysis membrane of a catalyst from a solution containing it.
  • the homogeneous catalysis oxidation processes are relatively numerous.
  • the oxidation of the cycloalkanes to the corresponding diacids can be carried out by using a soluble salt of heavy metals such as cobalt or manganese.
  • Patent FR-A-2,722,783 describes a process for the separation and recycling of a cobalt catalyst, used for the oxidation of cyclohexane to adipic acid, after separation of the main reaction products from the reaction medium and minus part of the acetic acid solvent.
  • This process essentially consists of extract the majority of the catalyst using cyclohexane or a mixture of cyclohexane and acetic acid. This process is efficient and the recycled catalyst has not lost its activity. However, it involves significant amounts of solvent and requires several successive operations.
  • US Patent 4,680,098 describes a process for recovering cobalt ions and manganese, from a dilute aqueous solution also containing impurities, by separation in an electrodialyzer composed of units each having three compartments.
  • FR-A-1,591,176 describes a process for recovering catalysts and nitric acid present in the mother liquors resulting from the separation of the reaction mass obtained during the nitric oxidation of cyclohexanol and / or cyclohexanone, consisting in passing part of the mother liquors containing metallic salts, nitric acid and organic acids in a electrodialysis cell.
  • the metal catalysts used are copper salts or of vanadium.
  • Patent FR-A-2,026,288 describes a process for recovering a part significant amount of nitric acid and metal ions from an acidic residual liquid produced during the manufacture of adipic acid by oxidation of cyclohexanone or cyclohexanol to liquid phase, comprising the introduction of this liquid into an electrodialysis device consisting of one or more electrodialyzers, to recover nitric acid and ions metallic in a collecting liquid which can be water or a dilute solution nitric acid.
  • the metal catalysts used are copper or vanadium.
  • the present invention relates to the separation of a homogeneous catalyst used works in the oxidation of cyclohexane by oxygen and therefore does not contain any acid nitric. It relates more precisely to a process for the separation of a catalyst homogeneous dissolved in a medium also containing at least one aliphatic diacid and resulting from an oxidation reaction of cycloalkanes by molecular oxygen, the cobalt-containing catalyst, characterized in that the separation is carried out by electrodialysis membrane in an electrodialysis machine which has cells with two compartments.
  • Homogeneous catalysts are the compounds of metals usually used for the oxidation of cycloalkanes to aliphatic diacids. These are more particularly catalysts containing cobalt, alone or with other metals such as manganese, copper, iron, vanadium, cerium or mixtures of these metals. These metals are in the form of compounds soluble in the oxidation reaction medium cycloalkanes. Such compounds are hydroxides, oxides, salts organic or mineral. The preferred compounds are the cobalt salts, alone or combined with other metal-based compounds such as manganese and / or copper and / or iron and / or cerium and / or vanadium.
  • cobalt salts mention may be made of cobalt chloride, cobalt bromide, cobalt nitrate, cobalt carboxylates such as acetate cobalt, cobalt propionate, cobalt adipate, cobalt glutarate, succinate cobalt.
  • cobalt chloride cobalt bromide
  • cobalt nitrate cobalt carboxylates
  • cobalt carboxylates such as acetate cobalt, cobalt propionate, cobalt adipate
  • cobalt glutarate succinate cobalt.
  • One of the most commonly used solvents for the oxidation of cycloalkanes is acetic acid, cobalt acetate tetrahydrate is particularly preferred.
  • the mixture subjected to the membrane electrodialysis contains at least one diacid formed during the oxidation of cycloalkane and frequently one or more other diacids also formed as by-products. It can also contain all of the reaction byproducts.
  • the catalyst is used for the oxidation of cyclohexane, mostly adipic acid, but also acid glutaric and succinic acid, as well as varying amounts of cyclohexanol, cyclohexanone, cyclohexyl esters, lactones, acids hydroxy.
  • the oxidation reaction is generally carried out in a solvent organic, preferably acetic acid for the oxidation of cyclohexane, or the case optionally solvent-free
  • the mixture to be electrodialysed preferably contains water.
  • the medium in which the homogeneous catalyst is found therefore comprises preferably water, the solvent having optionally been used in the process which has leads to the solution to be treated which can be entirely or partially replaced by water before electrodialysis.
  • water represents from 10% to 100% of the environment solvent for the solution subjected to electrodialysis and preferably from 50% to 100% of this solvent medium.
  • electrodialysis is a process which allows, under the influence of a continuous electric field, to extract by migration through membranes ion exchangers the ionized species contained in the solution to be treated.
  • the electrodialysis device used is made up of different compartments alternately delimited by cationic membranes and anionic membranes. These compartments are divided into dilution compartments (D) which deplete the compound to be separated, that is to say the catalyst in the process of the invention, and in concentration compartments (C) which, conversely are enriched with compound to be separated.
  • D dilution compartments
  • C concentration compartments
  • the cations of the solution to be treated migrate towards the cathode leaving the compartment (D) where they are, through a cation exchange membrane (cation membrane).
  • cation membrane cation membrane
  • anionic membrane anion exchange membrane
  • the anions migrate to the anode through an anionic membrane and pass into a compartment (C) adjacent, which they cannot then leave due to the presence of the following cationic membrane.
  • a electrodialyzer comprises a stack of several cells. This number of cells per electrodialyzer is generally as high as possible. For example, this number can advantageously vary between 10 and 500 cells.
  • anionic and cationic membranes are arranged alternatively in a filter press type system.
  • the homopolar membranes used in the process of the invention divide into two large families, according to their method of manufacture.
  • heterogeneous membranes prepared from resins ion exchangers, mixed with a binder such as polyvinyl chloride, polyethylene Or other.
  • a binder such as polyvinyl chloride, polyethylene Or other.
  • the assembly thus formed can coat a weft such as for example a fabric polyester or polyacrylonitrile.
  • the chemical method generally consists in functionalizing a latex a polymer comprising aromatic rings, such as styrene / divinylbenzene or styrene / butadiene copolymers.
  • the functionalized latex is then used to coat a weft as for heterogeneous membranes.
  • the radiochemical method generally involves the grafting, under the influence of radiation, of an aromatic compound, such as styrene, on an inert support such as a sheet of polyethylene or polytetrafluoroethylene.
  • the aromatic nucleus is then functionalized as in the chemical method.
  • Cation exchange membranes (cationic membranes) contain strong acid groups, most often sulfonate groups, or weak acid groups, often carboxylate groups. More rarely, the acid groups can be PO 3 2- , HPO 2 - , AsO 3 2- , SeO 3 - groups .
  • Anion exchange membranes (anionic membranes) have strong basic groups, most often quaternary ammonium groups, or weak basic groups, most often amine groups. More rarely the basic groups can be phosphonium groups quaternary or sulfonium groups.
  • the cationic membranes preferably comprise strong acid groups and among these preferably groups sulfonates and anionic membranes preferably contain groups strong bases and among these preferably ammonium groups quaternary.
  • the electrodialyzer naturally includes a cathode and an anode.
  • the anode is made of materials conventionally used in electrodialysis, for example graphite, titanium coated with precious metals or oxides of precious metals, in particular platinum titanium.
  • the cathode is also made up of materials conventionally used in electrodialysis, for example in graphite, stainless steel, nickel.
  • the electrodialyzer is supplied with the at least partially aqueous solution to treat. It is also necessary to circulate at the anode a solution of an anolyte and at the cathode a solution of a catholyte. These solutions are often a solution single electrolyte. In the present process, a single electrolyte circuit is suitable well. The role of the electrolyte solution is to ensure sufficient conductivity. Of preferably, this conductivity will be equal to or greater than 20 millisiemens per centimeter (mS / cm), without this lower limit being considered as critical for the setting of the present process.
  • mS / cm millisiemens per centimeter
  • the electrolyte used is an ionizable compound such as a salt, an acid or a base.
  • the electrolyte is preferably chosen from non-electroactive compounds. Thus, for example, it is preferable not to use industrially chlorides which would generate chlorine at the anode.
  • electrolytes examples include neutral salts such as sulfates, acids like sulfamic acid, carboxylic acids soluble in water, sulfuric acid.
  • a salt of the metal can also be used as the electrolyte.
  • catalyst more particularly a cobalt salt, such as for example acetate cobalt.
  • the voltage applied to the electrodialyzer must be such as to avoid polarization of the system, that is to say a dissociation of water under the effect of an electric field too intense.
  • a voltage of 0.5 volt to 2.5 volt / cell and preferably 0.5 volt at 1.5 volt / cell is appropriate.
  • the polarization effect can be reduced by increasing the turbulence of the liquid, by the use of thin cells jointly with dividing frames.
  • the temperature at which the process of the invention is carried out is situated in a field compatible with the stability of the membranes. Indeed, if in principle high temperatures are favorable, increasing electrolytic mobility and reducing the viscosity of the solution to be treated, increasing the temperature decreases the service life of membranes. We will therefore preferably operate at a temperature less than or equal to 50 ° C and more particularly between 20 ° C and 40 ° C.
  • the electrodialyzer can operate in different ways. He can first operate continuously (direct pass operation), the solution to be treated continuously crossing the stack; several stages are then arranged in series if the processing rate to obtain requires it. It can also operate discontinuously (recirculation operation), the solution to be treated recirculates on a tank until that the desired treatment rate is obtained. Finally it can work in passage direct with partial recirculation.
  • reaction mixture in which the homogeneous catalyst is to be separated as well as the diacids, comes essentially, as has been indicated previously, processes for the oxidation of cycloalkanes to the corresponding diacids.
  • processes for the oxidation of cycloalkanes to the corresponding diacids For simplicity, it will generally be discussed in the following description of the oxidation cyclohexane to adipic acid, leading to the formation of smaller amounts, but nevertheless important, of glutaric acid and succinic acid.
  • This separation can be carried out in a known manner, for example by precipitating adipic acid by cooling this mixture.
  • the remaining solution is then taken up in water, after possibly a partial or total elimination of the organic solvent which it may contain, in order to be subjected to the electrodialysis according to the invention.
  • one electrodialyses contains from 0.0001 mol to 1 mole of catalyst per kilogram, from 0.001 mole to 1 mole of glutaric acid per kilogram, from 0.001 mole to 1 mole of succinic acid per kilogram and 0.001 mole to 1 mole of adipic acid per kilogram.
  • the electrodialyzer used consists of a stack of 10 cells of 2 dm 2 of active surface, each composed of a compartment into which the solution to be treated is introduced (compartment D where said solution will be diluted in catalyst) and a compartment C which will receive the catalyst during the electrodialysis.
  • the electrolyte consists of an aqueous solution of sulfamic acid, having a conductivity of 20 mS / cm at 20 ° C.
  • the circulation rate of this solution is 400 l / h and its volume is 2 l.
  • the circulation rate of this solution in compartments D is 180 l / h.
  • the solution which circulates in compartments C and which will receive the cobalt salt is initially an aqueous solution of sodium chloride at 5 g / l; it has a volume of 1.6 I and it circulates with a flow of 180 l / h.
  • the initial conductivity of each of the solutions in compartments C is 10 mS / cm.
  • the electrodialysis is carried out at an imposed voltage of 18 V.
  • Table 1 collates the results of the measurements relating to pH, conductivity and volume of solutions.
  • L1 represents the solution of compartments D, also called food solution
  • L2 represents the solution of compartments C, also called concentrated solution
  • L3 represents the solution of the electrolyte.
  • the purpose of this example is to prepare a solution to be implemented in the process for separating the catalyst by electrodialysis.
  • the nitrogen pressure is brought to 20 bar (2 MPa), stirring is started (800 rpm) and the temperature is brought to 120 ° C in 29 minutes. The nitrogen is then replaced by 20 bar of air at 4% oxygen.
  • the gas flow outlet is set at 250 liters / hour.
  • the temperature suddenly rises to 106 ° C and the oxygen begins to be consumed.
  • the content is brought in oxygen from the air at the inlet at 16%.
  • the oxygen content at the outlet of the autoclave remains less than 5% during the entire test.
  • the average temperature in the autoclave is maintained at 106-107 ° C.
  • reaction mixture comprising approximately 5700 g of adipic acid and consisting of an acetic phase of 35.3 kg and a 10.3 kg cyclohexane phase.
  • the liquid level in the autoclave is kept constant using a probe level.
  • the reaction mixture is collected in a glass container heated to 70C, thanks to a pneumatic bottom valve.
  • the separation of the two phases of the reaction mixture obtained is carried out at 70 ° C.
  • the acetic phase is concentrated to a mass of approximately 19 kg.
  • the acid adipic crystallizes and is separated by filtration. It is recrystallized from water (we get 4.2 kg of purified adipic acid).
  • the mixture of acetic and aqueous solutions from crystallization and the recrystallization of adipic acid represents approximately 11.5 kg. This mixture is concentrated to approximately 50% of its initial mass, then is diluted by approximately 2 times its body of water. By decantation, part of the cyclohexanone compounds are removed, cyclohexanol, esters.
  • the electrodialyzer used consists of a stack of 10 cells of 2 dm 2 of active surface, each composed of a compartment into which the hydroacetic solution to be treated prepared in example 2 is introduced (compartment D where said solution will be diluted in catalyst) and a compartment C which will receive the cobalt catalyst during the electrodialysis.
  • the electrolyte consists of an aqueous solution of sulfamic acid, having a conductivity of 20 mS / cm at 20 ° C.
  • the circulation rate of this solution is 400 l / h and its volume is 2 l.
  • the hydroacetic solution to be treated has a volume of 1.6 I (composition indicated in example 2).
  • the circulation rate of this solution in compartments D is 180 l / h.
  • the solution which circulates in compartments C and which will receive the cobalt salt is initially an aqueous solution of Co acetate tetrahydrate at 10 g / l, to have a initial conductivity of 3.5 to 4 mS / cm; it has a volume of 1.6 I and it circulates with a flow rate of 180 l / h.
  • the electrodialysis is carried out at an imposed voltage of 18 V.
  • Cobalt is measured by atomic absorption and the diacids and other organic compounds by vapor chromatography. We also tracks pH, conductivity and volume of solutions.
  • Example 1 the food solution depletes in water; this is explained by the fact that the ions that migrate are hydrated and that at the end of the test the difference in conductivity between the food solution and the solution concentrated is important (osmosis phenomenon).
  • Table 3 collates the results relating to the catalyst Co;
  • Table 4 collates the results relating to the organic compounds present in the solution to be treated.
  • the electrodialyzer used is the same as for Example 3 and the solution hydroacetic to be treated is that which was prepared in Example 2.
  • the solution which circulates in compartments C and which will receive the cobalt salt is initially the L2 solution obtained in a previous electrodialysis test of a part of the solution prepared in Example 2 and the L3 electrolyte solution comes from also from this same previous essay.
  • Example 1 the food solution depletes in water; this is explained by the fact that the ions that migrate are hydrated and that at the end of the test the difference in conductivity between the food solution and the solution concentrated is important (osmosis phenomenon).
  • Table 5 collates the results relating to the catalyst Co;
  • Table 6 collates the results relating to the organic compounds present in the solution to be treated.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Health & Medical Sciences (AREA)
  • Urology & Nephrology (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Catalysts (AREA)

Description

La présente invention concerne un procédé de séparation par électrodialyse membranaire d'un catalyseur à partir d'une solution le contenant.The present invention relates to a method of separation by electrodialysis membrane of a catalyst from a solution containing it.

Plus précisément, elle concerne la séparation d'un catalyseur mis en oeuvre dans une réaction d'oxydation par l'oxygène moléculaire en phase homogène.More specifically, it relates to the separation of a catalyst used in an oxidation reaction with molecular oxygen in a homogeneous phase.

Les procédés d'oxydation en catalyse homogène sont relativement nombreux. Ainsi l'oxydation des cycloalcanes en diacides correspondants peut être réalisée en utilisant un sel soluble de métaux lourds comme le cobalt ou le manganèse.The homogeneous catalysis oxidation processes are relatively numerous. Thus the oxidation of the cycloalkanes to the corresponding diacids can be carried out by using a soluble salt of heavy metals such as cobalt or manganese.

Le brevet US 2 223 493, publié en décembre 1940, décrit l'oxydation d'hydrocarbures cycliques en diacides correspondants, en phase liquide comportant généralement de l'acide acétique, à une température d'au moins 60°C, à l'aide d'un gaz contenant de l'oxygène et en présence d'un catalyseur d'oxydation tel qu'un composé du cobalt. Ce brevet prévoit un séparation de l'acide adipique formé par cristallisation, mais n'enseigne rien sur la manière de recycler le catalyseur, dans une nouvelle opération d'oxydation, ni a fortiori sur l'activité qu'aurait un catalyseur recyclé une ou plusieurs fois.US Patent 2,223,493, published in December 1940, describes oxidation of cyclic hydrocarbons to corresponding diacids, in the liquid phase comprising usually acetic acid, at a temperature of at least 60 ° C, using a gas containing oxygen and in the presence of an oxidation catalyst such as a compound of cobalt. This patent provides for separation of the adipic acid formed by crystallization, but teaches nothing about how to recycle the catalyst in a new operation oxidation, let alone on the activity that would have a catalyst recycled one or more times.

Le brevet FR-A-2 722 783 décrit un procédé de séparation et de recyclage d'un catalyseur au cobalt, ayant servi pour l'oxydation du cyclohexane en acide adipique, après séparation du milieu réactionnel des principaux produits de la réaction et d'au moins une partie du solvant acide acétique. Ce procédé consiste essentiellement à extraire la majorité du catalyseur à l'aide de cyclohexane ou d'un mélange de cyclohexane et d'acide acétique. Ce procédé est efficace et le catalyseur recyclé n'a pas perdu de son activité. Cependant il fait intervenir des quantités importantes de solvant et nécessite plusieurs opérations successives.Patent FR-A-2,722,783 describes a process for the separation and recycling of a cobalt catalyst, used for the oxidation of cyclohexane to adipic acid, after separation of the main reaction products from the reaction medium and minus part of the acetic acid solvent. This process essentially consists of extract the majority of the catalyst using cyclohexane or a mixture of cyclohexane and acetic acid. This process is efficient and the recycled catalyst has not lost its activity. However, it involves significant amounts of solvent and requires several successive operations.

Il apparaít donc souhaitable de disposer d'un procédé de séparation d'un catalyseur homogène dissous dans un milieu réactionnel, qui soit aussi efficace tout en étant de mise en oeuvre plus simple.It therefore appears desirable to have a process for separating a homogeneous catalyst dissolved in a reaction medium, which is also effective while being of simpler implementation.

Le brevet US 4,680,098 décrit un procédé de récupération d'ions cobalt et manganèse, à partir d'une solution aqueuse diluée contenant également des impuretés, par séparation dans un électrodialyseur composé d'unités ayant chacune trois compartiments.US Patent 4,680,098 describes a process for recovering cobalt ions and manganese, from a dilute aqueous solution also containing impurities, by separation in an electrodialyzer composed of units each having three compartments.

Le brevet FR-A-1 591 176 décrit un procédé de récupération des catalyseurs métalliques et de l'acide nitrique présents dans les eaux-mères résultant de la séparation de la masse réactionnelle obtenue lors de l'oxydation nitrique de cyclohexanol et/ou de cyclohexanone, consistant à faire passer une partie des eaux-mères contenant les sels métalliques, l'acide nitrique et les acides organiques dans une cellule d'électrodialyse. Les catalyseurs métalliques utilisés sont des sels de cuivre ou de vanadium. FR-A-1,591,176 describes a process for recovering catalysts and nitric acid present in the mother liquors resulting from the separation of the reaction mass obtained during the nitric oxidation of cyclohexanol and / or cyclohexanone, consisting in passing part of the mother liquors containing metallic salts, nitric acid and organic acids in a electrodialysis cell. The metal catalysts used are copper salts or of vanadium.

Le brevet FR-A-2 026 288 décrit un procédé de récupération d'une partie importante d'acide nitrique et d'ions métalliques d'un liquide résiduel acide produit lors de la fabrication d'acide adipique par oxydation de la cyclohexanone ou du cyclohexanol en phase liquide, comprenant l'introduction de ce liquide dans un dispositif d'électrodialyse consistant en un ou plusieurs électrodialyseurs, pour récupérer l'acide nitrique et les ions métalliques dans un liquide récupérateur qui peut être de l'eau ou une solution diluée d'acide nitrique. Les catalyseurs métalliques utilisés sont des sels de cuivre ou de vanadium.Patent FR-A-2,026,288 describes a process for recovering a part significant amount of nitric acid and metal ions from an acidic residual liquid produced during the manufacture of adipic acid by oxidation of cyclohexanone or cyclohexanol to liquid phase, comprising the introduction of this liquid into an electrodialysis device consisting of one or more electrodialyzers, to recover nitric acid and ions metallic in a collecting liquid which can be water or a dilute solution nitric acid. The metal catalysts used are copper or vanadium.

Ces deux procédés sont très semblables, voire identiques, et mettent en oeuvre des solutions contenant de fortes concentrations en acide nitrique. Cette particularité favorise considérablement la séparation des sels métalliques, sous forme de nitrates, des acides carboxyliques non disssociés.These two processes are very similar, even identical, and use solutions containing high concentrations of nitric acid. This peculiarity considerably promotes the separation of metal salts, in the form of nitrates, non-dissociated carboxylic acids.

La présente invention, telle que définie dans la revendication 1, concerne la séparation d'un catalyseur homogène mis en oeuvre dans l'oxydation du cyclohexane par l'oxygène et ne comportant donc pas d'acide nitrique. Elle concerne plus précisément un procédé de séparation d'un catalyseur homogène dissous dans un milieu contenant aussi au moins un diacide aliphatique et issu d'une réaction d'oxydation des cycloalcanes par l'oxygène moléculaire, le catalyseur contenant du cobalt, caractérisé en ce que la séparation est effectuée par électrodialyse membranaire dans un appareil d'électrodialyse qui comporte des cellules à deux compartiments.The present invention, as defined in claim 1, relates to the separation of a homogeneous catalyst used works in the oxidation of cyclohexane by oxygen and therefore does not contain any acid nitric. It relates more precisely to a process for the separation of a catalyst homogeneous dissolved in a medium also containing at least one aliphatic diacid and resulting from an oxidation reaction of cycloalkanes by molecular oxygen, the cobalt-containing catalyst, characterized in that the separation is carried out by electrodialysis membrane in an electrodialysis machine which has cells with two compartments.

Les catalyseurs homogènes sont les composés des métaux habituellement utilisés pour l'oxydation des cycloalcanes en diacides aliphatiques. Ce sont plus particulièrement les catalyseurs contenant du cobalt, seul ou avec d'autres métaux tels que le manganèse, le cuivre, le fer, le vanadium, le cérium ou les mélanges de ces métaux. Ces métaux sont sous forme de composés solubles dans le milieu réactionnel d'oxydation des cycloalcanes. De tels composés sont les hydroxydes, les oxydes, les sels organiques ou minéraux. Les composés préférés sont les sels de cobalt, seuls ou associés à d'autres composés à base de métaux tels que le manganèse et/ou le cuivre et/ou le fer et/ou le cérium et/ou le vanadium.Homogeneous catalysts are the compounds of metals usually used for the oxidation of cycloalkanes to aliphatic diacids. These are more particularly catalysts containing cobalt, alone or with other metals such as manganese, copper, iron, vanadium, cerium or mixtures of these metals. These metals are in the form of compounds soluble in the oxidation reaction medium cycloalkanes. Such compounds are hydroxides, oxides, salts organic or mineral. The preferred compounds are the cobalt salts, alone or combined with other metal-based compounds such as manganese and / or copper and / or iron and / or cerium and / or vanadium.

A titre d'exemples de ces sels de cobalt, on peut citer le chlorure de cobalt, le bromure de cobalt, le nitrate de cobalt, les carboxylates de cobalt comme l'acétate de cobalt, le propionate de cobalt, l'adipate de cobalt, le glutarate de cobalt, le succinate de cobalt. L'un des solvants utilisés le plus souvent pour l'oxydation des cycloalcanes étant l'acide acétique, l'acétate de cobalt tétrahydraté est particulièrement préféré.As examples of these cobalt salts, mention may be made of cobalt chloride, cobalt bromide, cobalt nitrate, cobalt carboxylates such as acetate cobalt, cobalt propionate, cobalt adipate, cobalt glutarate, succinate cobalt. One of the most commonly used solvents for the oxidation of cycloalkanes is acetic acid, cobalt acetate tetrahydrate is particularly preferred.

Le mélange soumis à l'électrodialyse membranaire contient au moins un diacide formé lors de l'oxydation du cycloalcane et fréquemment un ou plusieurs autres diacides également formés comme sous-produits. Il peut également contenir l'ensemble des sous-produits de la réaction. Lorsque le catalyseur est utilisé pour l'oxydation du cyclohexane, on obtient majoritairement de l'acide adipique, mais également de l'acide glutarique et de l'acide succinique, ainsi que des quantités plus ou moins importantes de cyclohexanol, de cyclohexanone, d'esters de cyclohexyle, de lactones, d'acides hydroxycarboxyliques.The mixture subjected to the membrane electrodialysis contains at least one diacid formed during the oxidation of cycloalkane and frequently one or more other diacids also formed as by-products. It can also contain all of the reaction byproducts. When the catalyst is used for the oxidation of cyclohexane, mostly adipic acid, but also acid glutaric and succinic acid, as well as varying amounts of cyclohexanol, cyclohexanone, cyclohexyl esters, lactones, acids hydroxy.

Bien que la réaction d'oxydation soit généralement réalisée dans un solvant organique, de préférence l'acide acétique pour l'oxydation du cyclohexane, ou le cas échéant sans solvant, le mélange à électrodialyser contient de préférence de l'eau.Although the oxidation reaction is generally carried out in a solvent organic, preferably acetic acid for the oxidation of cyclohexane, or the case optionally solvent-free, the mixture to be electrodialysed preferably contains water.

Le milieu dans lequel se trouve le catalyseur homogène comprend donc préférentiellement de l'eau, le solvant ayant éventuellement servi dans le procédé qui a conduit à la solution à traiter pouvant être entièrement ou partiellement remplacé par l'eau avant l'électrodialyse. Généralement l'eau représente de 10 % à 100 % du milieu solvant de la solution soumise à l'électrodialyse et de préférence de 50 % à 100 % de ce milieu solvant.The medium in which the homogeneous catalyst is found therefore comprises preferably water, the solvent having optionally been used in the process which has leads to the solution to be treated which can be entirely or partially replaced by water before electrodialysis. Generally water represents from 10% to 100% of the environment solvent for the solution subjected to electrodialysis and preferably from 50% to 100% of this solvent medium.

Schématiquement, l'électrodialyse est un procédé qui permet, sous l'influence d'un champ électrique continu, d'extraire par migration au travers de membranes échangeuses d'ions les espèces ionisées contenues dans la solution à traiter.Schematically, electrodialysis is a process which allows, under the influence of a continuous electric field, to extract by migration through membranes ion exchangers the ionized species contained in the solution to be treated.

L'appareil d'électrodialyse mis en oeuvre est constitué par différents compartiments délimités alternativement par des membranes cationiques et des membranes anioniques. Ces compartiments se divisent en compartiments de dilution (D) qui s'appauvrissent en composé à séparer, c'est-à-dire en catalyseur dans le procédé de l'invention, et en compartiments de concentration (C) qui à l'inverse s'enrichissent en composé à séparer.The electrodialysis device used is made up of different compartments alternately delimited by cationic membranes and anionic membranes. These compartments are divided into dilution compartments (D) which deplete the compound to be separated, that is to say the catalyst in the process of the invention, and in concentration compartments (C) which, conversely are enriched with compound to be separated.

En effet, sous l'action du champ électrique les cations de la solution à traiter migrent vers la cathode en sortant du compartiment (D) où ils se trouvent, à travers une membrane échangeuse de cations (membrane cationique). Lorsqu'ils sont passés dans le compartiment (C) suivant, ils ne peuvent pas le quitter en raison de la présence de la membrane échangeuse d'anions (membrane anionique) suivante. Simultanément les anions migrent vers l'anode en traversant une membrane anionique et passent dans un compartiment (C) adjacent, qu'ils ne peuvent ensuite pas quitter en raison de la présence de la membrane cationique suivante.Indeed, under the action of the electric field the cations of the solution to be treated migrate towards the cathode leaving the compartment (D) where they are, through a cation exchange membrane (cation membrane). When they passed in the next compartment (C), they cannot leave it due to the presence of the next anion exchange membrane (anionic membrane). Simultaneously the anions migrate to the anode through an anionic membrane and pass into a compartment (C) adjacent, which they cannot then leave due to the presence of the following cationic membrane.

Deux compartiments (C) et (D) adjacents forment une cellule d'électrodialyse. Un électrodialyseur comporte un empilement de plusieurs cellules. Ce nombre de cellules par électrodialyseur est de manière générale aussi élevé que possible. Par exemple, ce nombre peut varier avantageusement entre 10 et 500 cellules.Two adjacent compartments (C) and (D) form an electrodialysis cell. A electrodialyzer comprises a stack of several cells. This number of cells per electrodialyzer is generally as high as possible. For example, this number can advantageously vary between 10 and 500 cells.

En pratique, les membranes anioniques et cationiques sont disposées alternativement dans un système de type filtre-presse.In practice, the anionic and cationic membranes are arranged alternatively in a filter press type system.

Les membranes homopolaires utilisées dans le procédé de l'invention se divisent en deux grandes familles, selon leur mode de fabrication. The homopolar membranes used in the process of the invention divide into two large families, according to their method of manufacture.

Ce sont tout d'abord les membranes hétérogènes, préparées à partir de résines échangeuses d'ions, mélangées à un liant tel que polychlorure de vinyle, polyéthylène ou autre. L'ensemble ainsi formé peut enduire une trame comme par exemple un tissu de polyester ou de polyacrylonitrile.These are first of all heterogeneous membranes, prepared from resins ion exchangers, mixed with a binder such as polyvinyl chloride, polyethylene Or other. The assembly thus formed can coat a weft such as for example a fabric polyester or polyacrylonitrile.

Ce sont également les membranes homogènes, obtenues par introduction d'un groupement fonctionnel sur un support inerte, par greffage chimique ou radiochimique. La méthode chimique, la plus utilisée, consiste généralement à fonctionnaliser un latex d'un polymère comportant des noyaux aromatiques, tel que styrène/divinylbenzène ou styrène/butadiène. Le latex ainsi fonctionnalisé sert ensuite à enduire une trame comme pour les membranes hétérogènes. La méthode radiochimique comporte généralement le greffage, sous l'influence d'un rayonnement, d'un composé aromatique, tel que le styrène, sur un support inerte comme une feuille de polyéthylène ou de polytétrafluoroéthylène. Le noyau aromatique est ensuite fonctionnalisé comme dans la méthode chimique.These are also the homogeneous membranes, obtained by the introduction of a functional grouping on an inert support, by chemical or radiochemical grafting. The chemical method, the most used, generally consists in functionalizing a latex a polymer comprising aromatic rings, such as styrene / divinylbenzene or styrene / butadiene copolymers. The functionalized latex is then used to coat a weft as for heterogeneous membranes. The radiochemical method generally involves the grafting, under the influence of radiation, of an aromatic compound, such as styrene, on an inert support such as a sheet of polyethylene or polytetrafluoroethylene. The aromatic nucleus is then functionalized as in the chemical method.

Les membranes échangeuses de cations (membranes cationiques) comportent des groupements acides forts, le plus souvent des groupements sulfonates, ou des groupements acides faibles, souvent des groupements carboxylates. Plus rarement les groupements acides peuvent être des groupements PO3 2-, HPO2 -, AsO3 2-, SeO3 -.Cation exchange membranes (cationic membranes) contain strong acid groups, most often sulfonate groups, or weak acid groups, often carboxylate groups. More rarely, the acid groups can be PO 3 2- , HPO 2 - , AsO 3 2- , SeO 3 - groups .

Les membranes échangeuses d'anions (membranes anioniques) comportent des groupement basiques forts, le plus souvent des groupements ammonium quaternaire, ou des groupements basiques faibles, le plus souvent des groupements amines. Plus rarement les groupements basiques peuvent être des groupements phosphonium quaternaire ou des groupements sulfonium.Anion exchange membranes (anionic membranes) have strong basic groups, most often quaternary ammonium groups, or weak basic groups, most often amine groups. More rarely the basic groups can be phosphonium groups quaternary or sulfonium groups.

Dans le présent procédé, les membranes cationiques comportent de préférence des groupements acides forts et parmi ceux-ci préférentiellement des groupements sulfonates et les membranes anioniques comportent de préférence des groupements basiques forts et parmi ceux-ci préférentiellement des groupements ammonium quaternaire.In the present process, the cationic membranes preferably comprise strong acid groups and among these preferably groups sulfonates and anionic membranes preferably contain groups strong bases and among these preferably ammonium groups quaternary.

Outre les membranes, l'électrodialyseur comporte bien entendu une cathode et une anode. L'anode est constituée en des matériaux classiquement utilisés en électrodialyse, par exemple en graphite, en titane revêtu par des métaux précieux ou des oxydes de métaux précieux, notamment le titane platiné. La cathode est également constituée en des matériaux classiquement utilisés en électrodialyse, par exemple en graphite, en acier inoxydable, en nickel.In addition to the membranes, the electrodialyzer naturally includes a cathode and an anode. The anode is made of materials conventionally used in electrodialysis, for example graphite, titanium coated with precious metals or oxides of precious metals, in particular platinum titanium. The cathode is also made up of materials conventionally used in electrodialysis, for example in graphite, stainless steel, nickel.

L'électrodialyseur est alimenté avec la solution au moins partiellement aqueuse à traiter. Il est également nécessaire de faire circuler à l'anode une solution d'un anolyte et à la cathode une solution d'un catholyte. Ces solutions constituent souvent une solution unique d'électrolyte. Dans le présent procédé, un circuit unique d'électrolyte convient bien. Le rôle de la solution d'électrolyte est d'assurer une conductivité suffisante. De préférence, cette conductivité sera égale ou supérieure à 20 millisiemens par centimètre (mS/cm), sans que cette limite inférieure soit à considérer comme critique pour la mise en oeuvre du présent procédé.The electrodialyzer is supplied with the at least partially aqueous solution to treat. It is also necessary to circulate at the anode a solution of an anolyte and at the cathode a solution of a catholyte. These solutions are often a solution single electrolyte. In the present process, a single electrolyte circuit is suitable well. The role of the electrolyte solution is to ensure sufficient conductivity. Of preferably, this conductivity will be equal to or greater than 20 millisiemens per centimeter (mS / cm), without this lower limit being considered as critical for the setting of the present process.

L'électrolyte mis en oeuvre est un composé ionisable tel qu'un sel, un acide ou une base. L'électrolyte est de préférence choisi parmi les composés non électroactifs. Ainsi, par exemple, il est préférable de ne pas utiliser industriellement des chlorures qui généreraient du chlore à l'anode.The electrolyte used is an ionizable compound such as a salt, an acid or a base. The electrolyte is preferably chosen from non-electroactive compounds. Thus, for example, it is preferable not to use industrially chlorides which would generate chlorine at the anode.

On peut citer comme exemples d'électrolytes, des sels neutres comme les sulfates, des acides comme l'acide sulfamique, les acides carboxyliques solubles dans l'eau, l'acide sulfurique. On peut également utiliser comme électrolyte un sel du métal catalyseur, plus particulièrement un sel de cobalt, tel que par exemple l'acétate de cobalt.Examples of electrolytes that may be mentioned include neutral salts such as sulfates, acids like sulfamic acid, carboxylic acids soluble in water, sulfuric acid. A salt of the metal can also be used as the electrolyte. catalyst, more particularly a cobalt salt, such as for example acetate cobalt.

Dans le présent procédé, il faudra éviter d'utiliser des solutions d'électrolyte dont le pH pourrait conduire à la précipitation du composé métallique que l'on souhaite séparer par électrodialyse. C'est pourquoi, on choisira de préférence un électrolyte acide.In the present process, it is necessary to avoid using electrolyte solutions whose pH could lead to the precipitation of the metallic compound that one wishes to separate by electrodialysis. This is why, an acid electrolyte will preferably be chosen.

La tension appliquée à l'électrodialyseur doit être de nature à éviter la polarisation du système, c'est-à-dire une dissociation de l'eau sous l'effet d'un champ électrique trop intense. En général, une tension de 0,5 volt à 2,5 volt/cellule et de préférence de 0,5 volt à 1,5 volt/cellule est appropriée. L'effet de polarisation peut être diminué en augmentant la turbulence du liquide, par l'utilisation de cellules minces conjointement avec des cadres séparateurs. On préfère des cellules ayant une largeur de 0,5 mm à 2 mm et de préférence de 0,75 mm à 1,5 mm.The voltage applied to the electrodialyzer must be such as to avoid polarization of the system, that is to say a dissociation of water under the effect of an electric field too intense. In general, a voltage of 0.5 volt to 2.5 volt / cell and preferably 0.5 volt at 1.5 volt / cell is appropriate. The polarization effect can be reduced by increasing the turbulence of the liquid, by the use of thin cells jointly with dividing frames. Preferred are cells with a width of 0.5 mm to 2 mm and preferably from 0.75 mm to 1.5 mm.

La température à laquelle est mis en oeuvre le procédé de l'invention se situe dans un domaine compatible avec la stabilité des membranes. En effet, si en principe les températures élevées sont favorables, en accroissant la mobilité électrolytique et en réduisant la viscosité de la solution à traiter, l'augmentation de la température diminue la durée de vie des membranes. On opérera donc de préférence à une température inférieure ou égale à 50°C et plus particulièrement entre 20°C et 40°C.The temperature at which the process of the invention is carried out is situated in a field compatible with the stability of the membranes. Indeed, if in principle high temperatures are favorable, increasing electrolytic mobility and reducing the viscosity of the solution to be treated, increasing the temperature decreases the service life of membranes. We will therefore preferably operate at a temperature less than or equal to 50 ° C and more particularly between 20 ° C and 40 ° C.

L'électrodialyseur peut fonctionner de différentes façons. Il peut tout d'abord fonctionner en continu (fonctionnement en passage direct), la solution à traiter traversant en continu l'empilement ; plusieurs étages sont alors disposés en série si le taux de traitement à obtenir l'exige. Il peut aussi fonctionner en discontinu (fonctionnement en recirculation), la solution à traiter recirculant sur une cuve jusqu'à ce que le taux de traitement souhaité soit obtenu. Enfin il peut fonctionner en passage direct avec une recirculation partielle. The electrodialyzer can operate in different ways. He can first operate continuously (direct pass operation), the solution to be treated continuously crossing the stack; several stages are then arranged in series if the processing rate to obtain requires it. It can also operate discontinuously (recirculation operation), the solution to be treated recirculates on a tank until that the desired treatment rate is obtained. Finally it can work in passage direct with partial recirculation.

Le mélange réactionnel, dans lequel se trouve le catalyseur homogène à séparer ainsi que les diacides, provient essentiellement, comme cela à été indiqué précédemment, des procédés d'oxydation des cycloalcanes en diacides correspondants. Pour simplifier, il sera question généralement dans la description qui suit de l'oxydation du cyclohexane en acide adipique, conduisant à la formation de quantités plus faibles, mais néanmoins importantes, d'acide glutarique et d'acide succinique.The reaction mixture, in which the homogeneous catalyst is to be separated as well as the diacids, comes essentially, as has been indicated previously, processes for the oxidation of cycloalkanes to the corresponding diacids. For simplicity, it will generally be discussed in the following description of the oxidation cyclohexane to adipic acid, leading to the formation of smaller amounts, but nevertheless important, of glutaric acid and succinic acid.

Avant de traiter par électrodialyse un tel mélange, il est généralement avantageux de réaliser certaines opérations permettant en particulier de séparer la majeure partie de l'acide adipique, composé dont la préparation est visée.Before treating such a mixture by electrodialysis, it is generally advantageous perform certain operations, in particular to separate most of adipic acid, the compound whose preparation is targeted.

Cette séparation peut être effectuée de manière connue, par exemple en précipitant l'acide adipique par refroidissement de ce mélange.This separation can be carried out in a known manner, for example by precipitating adipic acid by cooling this mixture.

La solution restante est alors reprise par de l'eau, après éventuellement une élimination partielle ou totale du solvant organique qu'elle peut contenir, afin d'être soumise à l'électrodialyse selon l'invention.The remaining solution is then taken up in water, after possibly a partial or total elimination of the organic solvent which it may contain, in order to be subjected to the electrodialysis according to the invention.

Généralement la solution que l'on électrodialyse contient de 0,0001 mole à 1 mole de catalyseur par kilogramme, de 0,001 mole à 1 mole d'acide glutarique par kilogramme, de 0,001 mole à 1 mole d'acide succinique par kilogramme et de 0,001 mole à 1 mole d'acide adipique par kilogramme.Generally the solution that one electrodialyses contains from 0.0001 mol to 1 mole of catalyst per kilogram, from 0.001 mole to 1 mole of glutaric acid per kilogram, from 0.001 mole to 1 mole of succinic acid per kilogram and 0.001 mole to 1 mole of adipic acid per kilogram.

Les exemples qui suivent illustrent l'invention.The following examples illustrate the invention.

EXEMPLE 1EXAMPLE 1

L'électrodialyseur utilisé est constitué par un empilement de 10 cellules de 2 dm2 de surface active, composées chacune d'un compartiment où l'on introduit la solution à traiter (compartiment D où ladite solution sera diluée en catalyseur) et d'un compartiment C qui recevra le catalyseur au cours de l'électrodialyse.The electrodialyzer used consists of a stack of 10 cells of 2 dm 2 of active surface, each composed of a compartment into which the solution to be treated is introduced (compartment D where said solution will be diluted in catalyst) and a compartment C which will receive the catalyst during the electrodialysis.

Les membranes séparant chaque compartiment D du compartiment C adjacent sont :

  • membrane anionique de marque NEOSEPTA® AMX à groupements ammonium quaternaire,
  • membrane cationique de marque NEOSEPTA® CMX à groupements sulfonates.
The membranes separating each compartment D from the adjacent compartment C are:
  • NEOSEPTA® AMX brand anionic membrane with quaternary ammonium groups,
  • NEOSEPTA® CMX brand cationic membrane with sulfonate groups.

L'électrolyte est constitué par une solution aqueuse d'acide sulfamique, ayant une conductivité de 20 mS/cm à 20°C. Le débit de circulation de cette solution est de 400 l/h et son volume est de 2 l. The electrolyte consists of an aqueous solution of sulfamic acid, having a conductivity of 20 mS / cm at 20 ° C. The circulation rate of this solution is 400 l / h and its volume is 2 l.

La solution aqueuse à traiter a un volume de 1,6 I et elle contient au départ :

  • 0,18 mol/kg d'acide adipique
  • 0,87 mol/kg d'acide glutarique
  • 0,36 mol/kg d'acide succinique
  • 0,27 mol/kg de cobalt sous forme d'acétate de cobalt.
The aqueous solution to be treated has a volume of 1.6 I and it contains at the start:
  • 0.18 mol / kg adipic acid
  • 0.87 mol / kg glutaric acid
  • 0.36 mol / kg succinic acid
  • 0.27 mol / kg of cobalt in the form of cobalt acetate.

On a utilisé le mode de fonctionnement discontinu (fonctionnement en recirculation).We used the discontinuous operating mode (operating in recirculation).

Le débit de circulation de cette solution dans les compartiments D est de 180 l/h.The circulation rate of this solution in compartments D is 180 l / h.

La solution qui circule dans les compartiments C et qui va recevoir le sel de cobalt est au départ une solution aqueuse de chlorure de sodium à 5 g/l ; elle a un volume de 1,6 I et elle circule avec un débit de 180 l/h.The solution which circulates in compartments C and which will receive the cobalt salt is initially an aqueous solution of sodium chloride at 5 g / l; it has a volume of 1.6 I and it circulates with a flow of 180 l / h.

La conductivité initiale de chacune des solutions des compartiments C est de 10 mS/cm.The initial conductivity of each of the solutions in compartments C is 10 mS / cm.

L'électrodialyse est conduite à tension imposée de 18 V.The electrodialysis is carried out at an imposed voltage of 18 V.

Des échantillons des différentes solutions sont prélevés périodiquement afin de suivre l'évolution de l'opération. On dose le cobalt par absorption atomique et les diacides par chromatographie en phase vapeur. On suit également le pH, la conductivité et le volume des solutions.Samples of the different solutions are taken periodically in order to follow the progress of the operation. Cobalt is measured by atomic absorption and the diacids by vapor phase chromatography. We also follow the pH, the conductivity and the volume of solutions.

Le tableau 1 ci-après rassemble les résultats des mesures concemant le pH, la conductivité et le volume des solutions.Table 1 below collates the results of the measurements relating to pH, conductivity and volume of solutions.

Le tableau 2 ci-après rassemble les résultats concernant les concentrations en mol/kg des différents prélèvements. Par définition, L1 représente la solution des compartiments D, aussi appelée solution alimentaire, L2 représente la solution des compartiments C, aussi appelée solution concentrée et L3 représente la solution de l'électrolyte.Table 2 below collates the results concerning the concentrations of mol / kg of the different samples. By definition, L1 represents the solution of compartments D, also called food solution, L2 represents the solution of compartments C, also called concentrated solution and L3 represents the solution of the electrolyte.

Comme cela peut être constaté dans les résultats du tableau 1, la solution alimentaire s'appauvrit en eau ; cela s'explique par le fait que les ions qui migrent sont hydratés et qu'en fin d'essai la différence de conductivité entre la solution alimentaire et la solution concentrée est importante (phénomène d'osmose).As can be seen from the results in Table 1, the solution food depletes water; this is explained by the fact that the ions which migrate are hydrated and that at the end of the test the difference in conductivity between the food solution and the concentrated solution is important (osmosis phenomenon).

Pour établir des bilans précis, on exprimera dans le tableau 2 les résultats en tenant compte des variations de volume. Les résultats du tableau 2 sont exprimés en considérant que l'on part de 1 kg de flux à traiter.To establish precise balance sheets, we will express in Table 2 the results in taking into account variations in volume. The results of Table 2 are expressed in considering that we start with 1 kg of flux to be treated.

Le symbole "-" dans le tableau signifie que la mesure n'a pas été effectuée. Temps en min Solution prélevée Température en °C pH Conductivité en mS/cm Volume en ml 0 L1 20,0 3,5 10,7 1600 0 L2 20,0 4,6 10,1 1600 0 L3 20,0 - 20,0 2000 18 L1 - 3,5 9,6 1567 20 L2 - 4,7 14,1 1639 38 L1 - 3,2 7,6 1530 40 L2 27,2 4,7 16,4 1677 57 L1 28,4 2,9 5,1 1495 58 L2 - 4,9 17,8 1712 80 L1 - 2,1 1,9 1416 80 L2 - 4,8 18,8 1793 86 L1 30,2 2,0 1,8 1405 86 L2 - 4,8 18,9 1805 Temps en min Solution prélevée Co en mol/kg Acide adipique en mol/kg Acide glutarique en mol/kg Acide succinique en mol/kg 0 L1 0,267 0,183 0,869 0,355 0 L2 0 0 0 0 0 L3 0 0 0 0 0 Total 0,267 0,183 0,869 0,355 18 L1 0,192 0,184 0,867 0,340 20 L2 0,066 0 0 0,002 20 Total 0,258 0,184 0,867 0,342 38 L1 0,137 0,175 0,822 0,316 40 L2 0,127 0,005 0,050 0,036 40 Total 0,264 0,180 0,872 0,352 57 L1 0,064 0,174 0,827 0,306 58 L2 0,193 0 0,044 0,076 58 Total 0,257 0,174 0,871 0,382 80 L1 0,005 0,149 0,753 0,271 80 L2 0,251 0 0,082 0,080 80 Total 0,256 0,149 0,835 0,351 86 L1 0,0005 0,163 0,774 0,269 86 L2 0,244 0 0,081 0,078 86 L3 0,001 0 0 0,004 86 Total 0,245 0,163 0,855 0,351 The symbol "-" in the table means that the measurement has not been made. Time in min Solution taken Temperature in ° C pH Conductivity in mS / cm Volume in ml 0 L1 20.0 3.5 10.7 1600 0 L2 20.0 4.6 10.1 1600 0 L3 20.0 - 20.0 2000 18 L1 - 3.5 9.6 1567 20 L2 - 4.7 14.1 1639 38 L1 - 3.2 7.6 1530 40 L2 27.2 4.7 16.4 1677 57 L1 28.4 2.9 5.1 1495 58 L2 - 4.9 17.8 1712 80 L1 - 2.1 1.9 1416 80 L2 - 4.8 18.8 1793 86 L1 30.2 2.0 1.8 1405 86 L2 - 4.8 18.9 1805 Time in min Solution taken Co in mol / kg Adipic acid in mol / kg Glutaric acid in mol / kg Succinic acid in mol / kg 0 L1 0.267 0.183 0.869 0,355 0 L2 0 0 0 0 0 L3 0 0 0 0 0 Total 0.267 0.183 0.869 0,355 18 L1 0.192 0.184 0.867 0.340 20 L2 0.066 0 0 0,002 20 Total 0.258 0.184 0.867 0.342 38 L1 0,137 0,175 0.822 0.316 40 L2 0,127 0.005 0,050 0,036 40 Total 0.264 0,180 0.872 0,352 57 L1 0.064 0.174 0.827 0.306 58 L2 0,193 0 0.044 0,076 58 Total 0.257 0.174 0.871 0.382 80 L1 0.005 0.149 0.753 0.271 80 L2 0.251 0 0.082 0,080 80 Total 0.256 0.149 0.835 0.351 86 L1 0.0005 0.163 0.774 0.269 86 L2 0.244 0 0.081 0.078 86 L3 0,001 0 0 0,004 86 Total 0,245 0.163 0.855 0.351

EXEMPLE 2EXAMPLE 2 Oxydation du cyclohexane en acide adipiqueOxidation of cyclohexane to adipic acid

Cet exemple a pour but de préparer une solution à mettre en oeuvre dans le procédé de séparation du catalyseur par électrodialyse.The purpose of this example is to prepare a solution to be implemented in the process for separating the catalyst by electrodialysis.

Dans un autoclave de 1,5 litre chemisé en titane et équipé d'une turbine et de diverses ouvertures pour l'introduction des réactifs et des fluides ou pour l'évacuation des produits de la réaction et des fluides, on charge à température ambiante, après avoir préalablement purgé l'appareillage avec de l'azote :

  • acétate de Co tétrahydraté :   4,0 g
  • acide acétique :   359 g
  • cyclohexane :   289,7 g
  • acétaldéhyde :   1,2 g
Charging is carried out at room temperature in a 1.5 liter autoclave lined with titanium and equipped with a turbine and various openings for the introduction of the reagents and fluids or for the discharge of the reaction products and the fluids. after having previously purged the apparatus with nitrogen:
  • Co acetate tetrahydrate: 4.0 g
  • acetic acid: 359 g
  • cyclohexane: 289.7 g
  • acetaldehyde: 1.2 g

Après fermeture de l'autoclave, la pression d'azote est portée à 20 bar (2 MPa), l'agitation est mise en route (800 tours/min) et la température est amenée à 120°C en 29 minutes. L'azote est alors remplacé par 20 bar d'air à 4 % d'oxygène. Le débit gazeux de sortie est réglé à 250 litres/heure.After closing the autoclave, the nitrogen pressure is brought to 20 bar (2 MPa), stirring is started (800 rpm) and the temperature is brought to 120 ° C in 29 minutes. The nitrogen is then replaced by 20 bar of air at 4% oxygen. The gas flow outlet is set at 250 liters / hour.

Après une période d'induction de 10 min, pendant laquelle il n'y a pas de consommation d'oxygène, la température s'élève brutalement à 106°C et l'oxygène commence à être consommé. A l'aide d'un système de débitmètres, on amène la teneur en oxygène de l'air à l'entrée à 16 %. La teneur en oxygène à la sortie de l'autoclave reste inférieure à 5 % durant la totalité de l'essai. La température moyenne dans l'autoclave est maintenue à 106-107°C.After an induction period of 10 min, during which there is no oxygen consumption, the temperature suddenly rises to 106 ° C and the oxygen begins to be consumed. Using a flowmeter system, the content is brought in oxygen from the air at the inlet at 16%. The oxygen content at the outlet of the autoclave remains less than 5% during the entire test. The average temperature in the autoclave is maintained at 106-107 ° C.

Lorsque 50 litres d'oxygène ont été consommés (ce qui correspond à un taux de transformation du cyclohexane d'environ 20 %), on injecte en continu du cyclohexane (4,3 ml/min) et une solution acétique d'acétate de Co tétrahydraté à 1,1 % en poids par poids (débit de 3,9 ml/min).When 50 liters of oxygen have been consumed (which corresponds to a rate of cyclohexane transformation of about 20%), cyclohexane is continuously injected (4.3 ml / min) and an acetic solution of Co acetate tetrahydrate at 1.1% by weight per weight (flow rate of 3.9 ml / min).

L'injection est poursuivie jusqu'à l'obtention d'un mélange réactionnel comprenant environ 5700 g d'acide adipique et constitué d'une phase acétique de 35,3 kg et d'une phase cyclohexanique de 10,3 kg.The injection is continued until a reaction mixture comprising approximately 5700 g of adipic acid and consisting of an acetic phase of 35.3 kg and a 10.3 kg cyclohexane phase.

Le niveau du liquide dans l'autoclave est maintenu constant à l'aide d'une sonde de niveau. Le mélange réactionnel est récupéré dans un récipient en verre chauffé à 70C, grace à une vanne pneumatique de fond asservie.The liquid level in the autoclave is kept constant using a probe level. The reaction mixture is collected in a glass container heated to 70C, thanks to a pneumatic bottom valve.

La séparation des deux phases du mélange réactionnel obtenu est effectuée à 70°C.The separation of the two phases of the reaction mixture obtained is carried out at 70 ° C.

La phase acétique est concentrée jusqu'à une masse de 19 kg environ. L'acide adipique cristallise et il est séparé par filtration. Il est recristallisé dans l'eau (on obtient ainsi 4,2 kg d'acide adipique purifié).The acetic phase is concentrated to a mass of approximately 19 kg. The acid adipic crystallizes and is separated by filtration. It is recrystallized from water (we get 4.2 kg of purified adipic acid).

Le mélange des solutions acétique et aqueuse provenant de la cristallisation et de la recristallisation de l'acide adipique représente environ 11,5 kg. Ce mélange est concentré à environ 50 % de sa masse initiale, puis est dilué par environ 2 fois sa masse d'eau. Par décantation, on élimine une partie des composés cyclohexanone, cyclohexanol, esters. The mixture of acetic and aqueous solutions from crystallization and the recrystallization of adipic acid represents approximately 11.5 kg. This mixture is concentrated to approximately 50% of its initial mass, then is diluted by approximately 2 times its body of water. By decantation, part of the cyclohexanone compounds are removed, cyclohexanol, esters.

On obtient ainsi une solution hydroacétique de composition suivante :

  • cobalt   0,4485 % en poids par poids
  • acide acétique   193 g par kg de solution
  • eau   626 g par kg de solution
  • acide adipique   41 g par kg de solution
  • acide glutarique   27,9 g par kg de solution
  • acide succinique   13,3 g par kg de solution
  • acide hydroxycaproïque   4,8 g par kg de solution
  • acide hydroxyadipique   9,4 g par kg de solution
  • cyclohexanone   10,6 g par kg de solution
  • cyclohexanol   5,7 g par kg de solution
  • acétate de cyclohexyle   3,4 g par kg de solution
  • butyrolactone   6,4 g par kg de solution
  • valérolactone   0,8 g par kg de solution
  • esters divers de cyclohexyle   41,2 mmol par kg de solution.
A hydroacetic solution of the following composition is thus obtained:
  • cobalt 0.4485% by weight by weight
  • acetic acid 193 g per kg of solution
  • water 626 g per kg of solution
  • adipic acid 41 g per kg of solution
  • glutaric acid 27.9 g per kg of solution
  • succinic acid 13.3 g per kg of solution
  • hydroxycaproic acid 4.8 g per kg of solution
  • hydroxyadipic acid 9.4 g per kg of solution
  • cyclohexanone 10.6 g per kg of solution
  • cyclohexanol 5.7 g per kg of solution
  • cyclohexyl acetate 3.4 g per kg of solution
  • butyrolactone 6.4 g per kg of solution
  • valerolactone 0.8 g per kg of solution
  • various cyclohexyl esters 41.2 mmol per kg of solution.

EXEMPLE 3EXAMPLE 3

L'électrodialyseur utilisé est constitué par un empilement de 10 cellules de 2 dm2 de surface active, composées chacune d'un compartiment où l'on introduit la solution hydroacétique à traiter préparée dans l'exemple 2 (compartiment D où ladite solution sera diluée en catalyseur) et d'un compartiment C qui recevra le catalyseur au cobalt au cours de l'électrodialyse.The electrodialyzer used consists of a stack of 10 cells of 2 dm 2 of active surface, each composed of a compartment into which the hydroacetic solution to be treated prepared in example 2 is introduced (compartment D where said solution will be diluted in catalyst) and a compartment C which will receive the cobalt catalyst during the electrodialysis.

Les membranes séparant chaque compartiment D du compartiment C adjacent sont :

  • membrane anionique de marque NEOSEPTA AMX à groupements ammonium quaternaire,
  • membrane cationique de marque NEOSEPTA CMX à groupements sulfonates.
The membranes separating each compartment D from the adjacent compartment C are:
  • NEOSEPTA AMX brand anionic membrane with quaternary ammonium groups,
  • NEOSEPTA CMX brand cationic membrane with sulfonate groups.

L'électrolyte est constitué par une solution aqueuse d'acide sulfamique, ayant une conductivité de 20 mS/cm à 20°C. Le débit de circulation de cette solution est de 400 l/h et son volume est de 2 l.The electrolyte consists of an aqueous solution of sulfamic acid, having a conductivity of 20 mS / cm at 20 ° C. The circulation rate of this solution is 400 l / h and its volume is 2 l.

La solution hydroacétique à traiter a un volume de 1,6 I (composition indiquée dans l'exemple 2).The hydroacetic solution to be treated has a volume of 1.6 I (composition indicated in example 2).

On a utilisé le mode de fonctionnement discontinu (fonctionnement en recirculation).We used the discontinuous operating mode (operating in recirculation).

Le débit de circulation de cette solution dans les compartiments D est de 180 l/h. The circulation rate of this solution in compartments D is 180 l / h.

La solution qui circule dans les compartiments C et qui va recevoir le sel de cobalt est au départ une solution aqueuse d'acétate de Co tétrahydraté à 10 g/l, pour avoir une conductivité initiale de 3,5 à 4 mS/cm ; elle a un volume de 1,6 I et elle circule avec un débit de 180 l/h.The solution which circulates in compartments C and which will receive the cobalt salt is initially an aqueous solution of Co acetate tetrahydrate at 10 g / l, to have a initial conductivity of 3.5 to 4 mS / cm; it has a volume of 1.6 I and it circulates with a flow rate of 180 l / h.

L'électrodialyse est conduite à tension imposée de 18 V.The electrodialysis is carried out at an imposed voltage of 18 V.

Des échantillons des différentes solutions sont prélevés périodiquement afin de suivre l'évolution de l'opération. On dose le cobalt par absorption atomique et les diacides et des autres composés organiques par chromatographie en phase vapeur. On suit également le pH, la conductivité et le volume des solutions.Samples of the different solutions are taken periodically in order to follow the progress of the operation. Cobalt is measured by atomic absorption and the diacids and other organic compounds by vapor chromatography. We also tracks pH, conductivity and volume of solutions.

Comme cela a déjà été signalé dans l'exemple 1, la solution alimentaire s'appauvrit en eau ; cela s'explique par le fait que les ions qui migrent sont hydratés et qu'en fin d'essai la différence de conductivité entre la solution alimentaire et la solution concentrée est importante (phénomène d'osmose).As already mentioned in Example 1, the food solution depletes in water; this is explained by the fact that the ions that migrate are hydrated and that at the end of the test the difference in conductivity between the food solution and the solution concentrated is important (osmosis phenomenon).

Pour établir des bilans précis, on exprimera dans les tableaux 3 et 4 les résultats en tenant compte des variations de volume. Les résultats sont exprimés en considérant que l'on part de 1 kg de flux à traiter.To establish precise balance sheets, the results will be expressed in Tables 3 and 4 taking into account variations in volume. The results are expressed by considering starting from 1 kg of flux to be treated.

Le tableau 3 rassemble les résultats relatifs au catalyseur Co ; le tableau 4 rassemble les résultats relatifs aux composés organiques présents dans la solution à traiter. Temps en min Solution prélevée Co en mol/kg Co %/Co initial dans L1 0 L1 0,070 100 0 L2 0,026 0 0 L3 0 0 0 Total 0,096 8 L1 0,037 53 9 L2 0,043 24,5 17 L1 0,017 24,5 18 L2 0,061 50 25 L1 0,004 6 26 L2 0,075 70 28 L1 0,002 3 28 L2 0,088 88,5 28 L3 0,006 8,5 28 Total 0,096 Table 3 collates the results relating to the catalyst Co; Table 4 collates the results relating to the organic compounds present in the solution to be treated. Time in min Solution taken Co in mol / kg Co% / Co initial in L1 0 L1 0,070 100 0 L2 0,026 0 0 L3 0 0 0 Total 0.096 8 L1 0,037 53 9 L2 0.043 24.5 17 L1 0,017 24.5 18 L2 0,061 50 25 L1 0,004 6 26 L2 0,075 70 28 L1 0,002 3 28 L2 0.088 88.5 28 L3 0.006 8.5 28 Total 0.096

Cet essai sur mélange issu d'un essai d'oxydation du cyclohexane en acide adipique confirme l'efficacité de la séparation par électrodialyse du catalyseur Co. Composés % restant par rapport à la solution L1 initiale temps 0 min temps 17 min temps 28 min acide adipique 100 97,5 98,5 acide glutarique 100 95 93,5 acide succinique 100 91,5 88 acide hydroxycaproïque 100 100 100 acide hydroxyadipique 100 89 88 cyclohexanol 100 96 100 acétate de cyclohexyle 100 91 97,5 cyclohexanone 100 97 98 butyrolactone 100 91 79 autres esters de cyclohexyle 100 100 100 acide acétique 100 96 96 This test on a mixture resulting from an oxidation test of cyclohexane to adipic acid confirms the efficiency of the separation by electrodialysis of the catalyst Co. compounds % remaining compared to the initial L1 solution time 0 min time 17 min time 28 min adipic acid 100 97.5 98.5 glutaric acid 100 95 93.5 succinic acid 100 91.5 88 hydroxycaproic acid 100 100 100 hydroxyadipic acid 100 89 88 cyclohexanol 100 96 100 cyclohexyl acetate 100 91 97.5 cyclohexanone 100 97 98 butyrolactone 100 91 79 other cyclohexyl esters 100 100 100 acetic acid 100 96 96

Les composés organiques restent très majoritairement dans la solution alimentaire.Most of the organic compounds remain in the solution food.

EXEMPLE 4EXAMPLE 4

L'électrodialyseur utilisé est le même que pour l'exemple 3 et la solution hydroacétique à traiter est celle qui a été préparée dans l'exemple 2.The electrodialyzer used is the same as for Example 3 and the solution hydroacetic to be treated is that which was prepared in Example 2.

La solution qui circule dans les compartiments C et qui va recevoir le sel de cobalt est au départ la solution L2 obtenue dans un essai antérieur d'électrodialyse d'une partie de la solution préparée dans l'exemple 2 et la solution d'électrolyte L3 provient également de ce même essai antérieur.The solution which circulates in compartments C and which will receive the cobalt salt is initially the L2 solution obtained in a previous electrodialysis test of a part of the solution prepared in Example 2 and the L3 electrolyte solution comes from also from this same previous essay.

Toutes les conditions de mise en oeuvre sont celles de l'exemple 3.All the conditions of implementation are those of Example 3.

Le but de cet essai est de montrer que l'on peut enrichir progressivement la solution concentrée des compartiments C en Co.The purpose of this essay is to show that we can gradually enrich the concentrated solution of compartments C in Co.

Comme cela a déjà été signalé dans l'exemple 1, la solution alimentaire s'appauvrit en eau ; cela s'explique par le fait que les ions qui migrent sont hydratés et qu'en fin d'essai la différence de conductivité entre la solution alimentaire et la solution concentrée est importante (phénomène d'osmose). As already mentioned in Example 1, the food solution depletes in water; this is explained by the fact that the ions that migrate are hydrated and that at the end of the test the difference in conductivity between the food solution and the solution concentrated is important (osmosis phenomenon).

Pour établir des bilans précis, on exprimera dans les tableaux 5 et 6 les résultats en tenant compte des variations de volume. Les résultats sont exprimés en considérant que l'on part de 1 kg de flux à traiter.To establish precise balance sheets, the results will be expressed in Tables 5 and 6 taking into account variations in volume. The results are expressed by considering starting from 1 kg of flux to be treated.

Le tableau 5 rassemble les résultats relatifs au catalyseur Co ; le tableau 6 rassemble les résultats relatifs aux composés organiques présents dans la solution à traiter. Temps en min Solution prélevée Co en mol/kg Co %/Co initial dans L1 0 L1 0,075 100 0 L2 0,086 0 0 L3 0,010 0 0 Total 0,171 7 L1 0,045 60 8 L2 0,098 15,5 16 L1 0,032 43 17 L2 0,120 46 25 L1 0,012 16 26 L2 0,133 63 30 L1 0,005 7 30 L2 0,153 89 30 L3 0,017 9 30 Total 0,175 Table 5 collates the results relating to the catalyst Co; Table 6 collates the results relating to the organic compounds present in the solution to be treated. Time in min Solution taken Co in mol / kg Co% / Co initial in L1 0 L1 0,075 100 0 L2 0.086 0 0 L3 0,010 0 0 Total 0.171 7 L1 0,045 60 8 L2 0.098 15.5 16 L1 0,032 43 17 L2 0,120 46 25 L1 0.012 16 26 L2 0.133 63 30 L1 0.005 7 30 L2 0.153 89 30 L3 0,017 9 30 Total 0,175

Cet exemple avec la mise en oeuvre d'une solution déjà concentrée en Co dans les compartiments C confirme l'efficacité de la séparation par électrodialyse du catalyseur Co et la possibilité d'obtenir des solutions encore plus concentrées en Co. Composés % restant par rapport à la solution L1 initiale temps 0 min temps 16 min temps 30 min acide adipique 100 104 95 acide glutarique 100 99,5 91,5 acide succinique 100 95 83,5 acide hydroxycaproïque 100 100 99 acide hydroxyadipique 100 100 88 cyclohexanol 100 99 100 acétate de cyclohexyle 100 92,5 100 cyclohexanone 100 97 100 butyrolactone 100 100 100 autres esters de cyclohexyle 100 100 93 acide acétique 100 95 95 This example with the use of a solution already concentrated in Co in compartments C confirms the efficiency of the separation by electrodialysis of the catalyst Co and the possibility of obtaining solutions even more concentrated in Co. compounds % remaining compared to the initial L1 solution time 0 min time 16 min time 30 min adipic acid 100 104 95 glutaric acid 100 99.5 91.5 succinic acid 100 95 83.5 hydroxycaproic acid 100 100 99 hydroxyadipic acid 100 100 88 cyclohexanol 100 99 100 cyclohexyl acetate 100 92.5 100 cyclohexanone 100 97 100 butyrolactone 100 100 100 other cyclohexyl esters 100 100 93 acetic acid 100 95 95

Claims (9)

  1. Process for the separation of a homogeneous metal catalyst dissolved in a medium also comprising at least one aliphatic diacid and resulting from a reaction for the oxidation of cycloalkanes by molecular oxygen, the catalyst comprising cobalt, characterized in that the separation is carried out by membrane electrodialysis in an electrodialysis device which comprises a stack of several cells, each cell being composed of two adjacent concentrating and diluting compartments, respectively (C) and (D), delimited alternately by cationic membranes and anionic membranes.
  2. Process according to claim 1, characterized in that the catalyst is chosen from catalysts comprising cobalt, alone or with other metals, such as manganese, copper, iron, vanadium, cerium or mixtures of these metals.
  3. Process according to claim 2, characterized in that the metals are in the form of compounds which are soluble in the reaction medium for the oxidation of cycloalkanes, such as organic or inorganic hydroxides, oxides or salts.
  4. Process according to one of claims 1 to 3, characterized in that the catalyst is chosen from cobalt salts, alone or in combination with other compounds based on metals such as manganese and/or copper and/or iron and/or cerium and/or vanadium.
  5. Process according to one of claims 1 to 4, characterized in that the mixture subjected to membrane electrodialysis comprises at least one diacid formed during the oxidation of the cycloalkane and one or more other diacids also formed as by-products, preferably adipic acid and also glutaric acid and succinic acid.
  6. Process according to one of claims 1 to 5, characterized in that the medium in which the homogeneous catalyst is found comprises water, the solvent which has optionally been used in the process which has led to the solution to be treated being able to be entirely or partially replaced by water before electrodialysis.
  7. Process according to claim 6, characterized in that water represents from 10% to 100% of the solvent medium of the solution subjected to electrodialysis and preferably from 50% to 100% of this solvent medium.
  8. Process according to one of claims 1 to 7, characterized in that the membranes are composed of a matrix to which functional groups are grafted, either anionic functional groups, such as sulphonate groups, for cationic membranes or cationic functional groups, such as quaternary ammonium groups, for anionic membranes.
  9. Process according to one of claims 1 to 8, characterized in that the solution which is subjected to electrodialysis comprises from 0.0001 mol to 1 mol of catalyst per kilogram, from 0.001 mol to 1 mol of glutaric acid per kilogram, from 0.001 mol to 1 mol of succinic acid per kilogram and from 0.001 mol to 1 mol of adipic acid per kilogram.
EP97919434A 1996-04-02 1997-03-27 Method for separating a catalyst by membrane electrodialysis Expired - Lifetime EP0914195B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9604379A FR2746671B1 (en) 1996-04-02 1996-04-02 METHOD FOR SEPARATING A CATALYST BY MEMBRANE ELECTRODIALYSIS
FR9604379 1996-04-02
PCT/FR1997/000559 WO1997036673A1 (en) 1996-04-02 1997-03-27 Method for separating a catalyst by membrane electrodialysis

Publications (2)

Publication Number Publication Date
EP0914195A1 EP0914195A1 (en) 1999-05-12
EP0914195B1 true EP0914195B1 (en) 2002-06-12

Family

ID=9491013

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97919434A Expired - Lifetime EP0914195B1 (en) 1996-04-02 1997-03-27 Method for separating a catalyst by membrane electrodialysis

Country Status (18)

Country Link
US (1) US6214190B1 (en)
EP (1) EP0914195B1 (en)
JP (1) JP3770620B2 (en)
CN (1) CN1126587C (en)
AR (1) AR006476A1 (en)
BR (1) BR9708416A (en)
CA (1) CA2250801C (en)
CZ (1) CZ291840B6 (en)
DE (1) DE69713334T2 (en)
ES (1) ES2177975T3 (en)
FR (1) FR2746671B1 (en)
ID (1) ID16798A (en)
PL (1) PL183407B1 (en)
RU (1) RU2181303C2 (en)
SK (1) SK283468B6 (en)
TW (1) TW515726B (en)
UA (1) UA46099C2 (en)
WO (1) WO1997036673A1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2775685B1 (en) * 1998-03-05 2000-12-29 Rhone Poulenc Fibres PROCESS FOR SEPARATION AND PURIFICATION OF ADIPIC ACID
US6340420B1 (en) * 1998-07-06 2002-01-22 Rpc Inc. Methods of treating the oxidation mixture of hydrocarbons to respective dibasic acids
US7255798B2 (en) * 2004-03-26 2007-08-14 Ion Power, Inc. Recycling of used perfluorosulfonic acid membranes
CN101468836A (en) * 2007-12-25 2009-07-01 通用电气公司 Electrodialysis plant and method
DE102013205508A1 (en) * 2013-03-27 2014-10-02 Siemens Aktiengesellschaft Plant and method for separating metals
CN105132005A (en) * 2015-07-28 2015-12-09 昆明理工大学 Preparation method for biodiesel
JP6917369B2 (en) * 2015-10-30 2021-08-11 中国石油化工股▲ふん▼有限公司 Wastewater treatment method and treatment system, and molecular sieve preparation method and production system
CN114164460B (en) * 2020-08-19 2023-05-02 中国石油化工股份有限公司 Treatment method for preparing adipic acid synthetic solution by direct oxidation of cyclohexane
CN112939765B (en) 2021-02-22 2022-08-09 湘潭大学 Method for co-producing adipic acid and cyclohexanone oxime from cyclohexane

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1591176A (en) * 1968-10-30 1970-04-27
GB1298814A (en) * 1968-12-16 1972-12-06 Ashahi Kasei Kogyo Kabushiki K A process for recovering acids and metal ions from waste liquors by electrodialysis
US4680098A (en) * 1985-03-18 1987-07-14 Amoco Corporation Aqueous recovery of cobalt or cobalt and manganese from solution also containing oxygenated aromatic compounds
US5282939A (en) * 1988-09-20 1994-02-01 Basf Aktiengesellschaft Removal of salts by electrodialysis
FR2722783B1 (en) * 1994-07-21 1996-08-30 Rhone Poulenc Chimie PROCESS FOR THE PREPARATION OF ADIPIC ACID BY DIRECT OXIDATION OF CYCLOHEXANE AND RECYCLING OF THE CATALYST

Also Published As

Publication number Publication date
BR9708416A (en) 1999-08-03
CZ291840B6 (en) 2003-06-18
US6214190B1 (en) 2001-04-10
EP0914195A1 (en) 1999-05-12
PL329130A1 (en) 1999-03-15
RU2181303C2 (en) 2002-04-20
TW515726B (en) 2003-01-01
CA2250801A1 (en) 1997-10-09
ES2177975T3 (en) 2002-12-16
JP3770620B2 (en) 2006-04-26
SK135898A3 (en) 1999-04-13
ID16798A (en) 1997-11-13
PL183407B1 (en) 2002-06-28
FR2746671B1 (en) 1998-09-25
WO1997036673A1 (en) 1997-10-09
FR2746671A1 (en) 1997-10-03
UA46099C2 (en) 2002-05-15
CA2250801C (en) 2001-12-25
CN1215350A (en) 1999-04-28
JP2000508227A (en) 2000-07-04
DE69713334T2 (en) 2003-01-02
AR006476A1 (en) 1999-08-25
CZ315698A3 (en) 1999-03-17
CN1126587C (en) 2003-11-05
DE69713334D1 (en) 2002-07-18
SK283468B6 (en) 2003-08-05

Similar Documents

Publication Publication Date Title
CN1443091A (en) Bipolar membrane electrodialysis of multivalent matal salts
US20050171381A1 (en) Process for preparing fluorocarboxylic acids
TWI481642B (en) Process for producing polycarbonate
JP2001508925A (en) Lithium recovery and purification
EP0914195B1 (en) Method for separating a catalyst by membrane electrodialysis
CN1247481A (en) Process for recovering organic hydroxides from waste solutions
JP2003523164A (en) Electrodialysis method for purification and recovery of gluconic acid derivatives
EP0349406B1 (en) Process for the industrial manufacture of aqueous solutions of glyoxylic acid
WO2004042117A1 (en) Process for electrochemical oxidation of ferrocyanide to ferricyanide
US20080047838A1 (en) Process for the Recovery of Acids
JPS62158231A (en) Manufacture of dichlorohydrin
CA1274250A (en) Purification and recovery of phenylalanine with calcium salts
MXPA03003689A (en) Process for improving the purity of quaternary ammonium hydroxides by electrolysis.
US7824538B2 (en) Process for improving the purity of quaternary ammonium hydroxides by electrolysis in a two-compartment cell
KR100485432B1 (en) Method for separating a catalyst by membrane electrodialysis
MXPA98007835A (en) Procedure for separating a catalyzer through membrane electrodialysis
JPS6157818B2 (en)
JPS5884997A (en) Ultrafiltration method
Sugai et al. Application of membrane separation method to concentrate products on the process producing environmentally adaptable deicer by means of wet oxidation of organic wastes
CH451101A (en) Process for the extraction of vanadium and copper from a waste aqueous liquor

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19980929

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE DE ES FR GB IE IT NL

AX Request for extension of the european patent

Free format text: RO PAYMENT 19980929

17Q First examination report despatched

Effective date: 19990630

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: RHODIA POLYAMIDE INTERMEDIATES

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE ES FR GB IE IT NL

AX Request for extension of the european patent

Free format text: RO PAYMENT 19980929

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REF Corresponds to:

Ref document number: 69713334

Country of ref document: DE

Date of ref document: 20020718

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: FRENCH

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20020829

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2177975

Country of ref document: ES

Kind code of ref document: T3

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: RHODIA POLYAMIDE INTERMEDIATES

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

NLT2 Nl: modifications (of names), taken from the european patent patent bulletin

Owner name: RHODIA POLYAMIDE INTERMEDIATES

26N No opposition filed

Effective date: 20030313

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20040310

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IE

Payment date: 20040312

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050328

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20051001

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20051001

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20110317

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20110303

Year of fee payment: 15

Ref country code: DE

Payment date: 20110323

Year of fee payment: 15

Ref country code: BE

Payment date: 20110311

Year of fee payment: 15

Ref country code: GB

Payment date: 20110323

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20110323

Year of fee payment: 15

BERE Be: lapsed

Owner name: *RHODIA POLYAMIDE INTERMEDIATES

Effective date: 20120331

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20120327

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20121130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120402

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120327

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120331

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 69713334

Country of ref document: DE

Effective date: 20121002

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120327

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20130710

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120328

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121002